D2D (Device to Device) technology refers to a communication approach in which direct communication is performed between two peer-to-peer user nodes. Direct-connect communication technology is applied importantly in a lot of areas where 3GPP has not standardized yet currently, including P2P (Peer to Peer) in a non-cellular operation mode Ad hoc which has been studied by the academic world continuously in recent years, and M2M (Machine to Machine) in loT (Internet of Things) which is a killer application that has always had great potential business requirements. In such a centralized or distributed network composed of D2D users, each user node can transmit and receive signals and may have a function of automatic routing (forwarding messages). Physical resources used for carrying communication may be configured by the network or may be obtained by competition between respective direct-communication communication terminals. It is a novel idea to enable UEs (user equipments) in a cellular system to communicate with each other directly without being switched over by a base station. Obviously, natural attenuation characteristics of a mobile propagation environment and lower transmission antennas of the user enable two UEs which directly communicate with each other to have a relatively small interference region. In this scenario, the users between which physical isolation (such as a degree of signal attenuation) reaches a certain degree can share the same resources (space, time, frequency, codeword, etc.), without causing severe interference with each other. Intuitionally, there may be a considerable number of users in each cell for the direct-connect communication, and introduction of the direct-connect communication technology in the cellular network may greatly improve space reuse efficiency of system resource, which may greatly relief pressure of scheduling network resources. Also, these D2D services are carried out under the configuration of the network, which is not only effective supplement to the existing cellular system making more efficient use of air interface resources, but also can incorporate various physical devices into the connection system, so that services, such as IoT, IoV (Internet of Vehicles), may be possibly implemented in the 3GPP cellular network framework. At the same time, since the cellular service can only run in a coverage area of the cellular network, and in an area without network coverage, the D2D service can work independently without the help of the base station, this can provide powerful means of rescuing in a timely manner for a disaster area (such as complete network paralysis caused by e.g. earthquake, flood etc.), which is a very powerful supplement to the existing cellular service. In view of this, the 3GPP has been promoting standardization of the D2D communication. As early as the beginning of 2013 in Malta RAN1 72nd meeting, 3GPP has decided to study on the D2D technology, and the 63rd plenary session of RAN hold in March 2014 at Fukuoka adopted a work issue of standardization of D2D services in LTE Rel-12. The LTE Rel-12 standard will support D2D services, and the present disclosure will address a problem of inter-symbol interference caused by coexistence of signals with different CP formats which are inevitably encountered.